He had his flaws but the former PM and his government look better all the time.

Monday marks a notable date in political history – the anniversary of April 9 1992, the last time that the Conservative Party managed to achieve victory at a general election. Right up to the BBC exit polls, it was assumed that Neil Kinnock’s Labour would win. But John Major, always underestimated by a sneering metropolitan media class, triumphed against the odds.

He won more votes – 14 million – than any other British prime minister has ever done. In popular terms, the margin of victory was immense. No less than 42 per cent of the voters came out for Major, 34 per cent for Kinnock. But the bias of the British electoral system hit the Conservatives hard.

Had Labour enjoyed that 8 per cent lead in the popular vote, it would have secured a parliamentary majority of more than 100. Unlucky Major ended up with a majority of just 21, which was whittled away over the coming years until his government ended in ignominy and defeat.

His administration has enjoyed a terrible reputation and remains associated with sleaze, incompetence, drift and weakness. But as time has passed this verdict has started to look unfair. History may yet be much kinder to John Major than many would have thought.

First, let’s take economic management. Because of the Black Wednesday fiasco of September 1992, when sterling was evicted from the exchange rate mechanism, this is regarded as a disaster. But the big picture tells a different story. Under Major’s two chancellors, Norman Lamont and Ken Clarke, Britain navigated her way very surely out of the deep recession of the early 1990s.

By 1997 employment was rising, growth stable, and the deficit was well under control, meaning that Gordon Brown as chancellor inherited the most benign economic scenario for any British government of the last century. The situation was so fundamentally strong that it took three successive Labour administrations to wreck it.

Major’s second great achievement concerns Northern Ireland. Tony Blair has taken all the credit for negotiating a peaceful solution to the Troubles. Much of it is deserved. But neither Blair nor anyone else has ever properly acknowledged the role played by Major in bringing the IRA to the peace table. Given that he was dependent on Unionist votes for his parliamentary majority, this was an act of sacrifice as well as political courage.

Public service reform is another area upon which Major can look back with pride. At the time, he was mocked as a useless meddler whose most substantive achievement was the derided Cones Hotline. But he was the first prime minister who seriously tried to tackle the vested interests that dominate the health service, introducing GP fundholding and patient choice.

He confronted the producer interests that have wrecked our education system, while Peter Lilley was the first welfare secretary to think seriously about the looming pensions crisis. Meanwhile, his home secretary, Michael Howard, bravely challenged the entrenched Home Office doctrine that rising crime was inevitable.

Sadly, most of these reforms were denounced by Labour – indeed, Blair deceitfully claimed that the Tories intended to abolish state pensions during the 1997 election campaign. Once in power, Labour scrapped Lilley’s pension plan and the city technology colleges, while putting the health strategy into reverse. It was only in his second term that Blair realised his mistake in departing from Major’s vision, and reintroduced Tory NHS and education proposals under different names.

Probably Major’s greatest achievement, though, was the Maastricht Treaty. It caused one of the biggest parliamentary revolts in the long history of the Conservative Party, and thus gravely weakened his authority. But viewed in hindsight, Britain’s opt-out over European monetary union stands as a visionary moment that has saved us from the humiliation and economic chaos now facing eurozone countries such as Spain and Italy. For that alone Major deserves a statue in Trafalgar Square – but once again he has been afforded very little credit.

Nobody could ever claim that Major was a great leader. He lacked personal presence, possessed an unbecoming petulance, and had no gift for language. But there is, nevertheless, a case to be made that he was one of our better peacetime prime ministers – a man who turned Britain into a better country.

Yet during the later stages of his premiership, Major was treated with almost universal, vicious derision. Calumny after calumny was heaped upon him, and though this campaign of laceration was led in Parliament by Blair’s brilliant New Labour opposition, the newspapers were all too happy to join in.

I look back with regret and mortification on my own record at that time. As an inexperienced political reporter on the Evening Standard, I just assumed that he was not up to it, and that his government was rotten: no prime minister of the modern era has been treated with such contempt.

It must be wounding for Sir John that the Conservative Party has never properly acknowledged his record. But the problem goes deeper than the personal feelings of a former prime minister. The up-and-coming generation of Tory politicians was formed by the Major experience. Like everybody else, they very naturally assumed that his government had been a dreadful failure, and that Blair’s New Labour provided the solutions.

Furthermore, all politicians want beyond anything else to secure power, and ambitious Tories were transfixed by New Labour’s electoral success. When David Cameron and George Osborne took the helm of the Tory party, they took Tony Blair as their model – and emphatically not John Major.

This decision was not surprising and perhaps even forgivable, but it is coming to look like a terrible mistake. As the Major and Blair administrations pass into history, we can measure their achievements more clearly. It is now evident that Major, though unsophisticated, inarticulate and devoid of charisma, led a serious government that sought to drive substantial change. By contrast, New Labour was driven by technique and saw politics as the art of manipulation and the construction of political “narrative”. It was dazzlingly successful in the short term, but its brilliant media story was never matched by real achievement.

So let’s look back again at that 1992 ballot, when John Major’s signature moment was standing on a soap box. It was the last general election before the modernisers captured British politics. The term “spin doctors” had not yet crossed the Atlantic, and party memberships, not focus groups, still played a role in determining policy. We had cabinet government, not a coterie of friends.

The Conservative party manifesto of that year reads well: a splendidly Tory document, it had a coherent message about low taxes, less regulation, and a smaller state. There were no clever strategems, nor attempts to “triangulate” the differences between parties. And, lo and behold, the Conservatives won. As David Cameron might well remember – after all, when that despised election was contested 20 years ago on Monday he was head of the political department at Conservative HQ.